/* ===================================================================
   AI 助学 v4 — 基于最新原版的完整重设计
   
   Design System: Ardot E-Learning
   - Sage Green #0D9488 primary / Marigold Orange #EA580C accent
   - Nunito 800 headings / DM Sans 500 body
   - Bento grid, tonal surface stacking, glass dock
   - Mirrors original HTML structure 100% for JS compatibility
   =================================================================== */

/* ==== Design Tokens (compatible names with original) ==== */
:root {
  /* Brand */
  --color-primary:       #0D9488;
  --color-primary-light: #CCFBF1;
  --color-primary-dark:  #0F766E;
  --color-primary-hover: #0F766E;

  /* Surfaces */
  --bg-page:      #F0FDFA;
  --bg-card:      #FFFFFF;
  --bg-input:     #F5FBF9;
  --color-bg:     #F0FDFA;
  --color-white:  #FFFFFF;

  /* Text */
  --color-text:          #134E4A;
  --color-text-secondary:#0F766E;
  --color-text-muted:    #64748B;

  /* Border */
  --color-border: #CCFBF1;

  /* Semantic */
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-danger:  #DC2626;
  --color-info:    #0D9488;

  /* Radius */
  --radius-sm:   10px;
  --radius-md:   14px;
  --radius-lg:   20px;
  --radius-xl:   28px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(19,78,74,0.06);
  --shadow-md: 0 4px 14px rgba(19,78,74,0.08);
  --shadow-lg: 0 8px 30px rgba(19,78,74,0.12);

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 12px;
  --space-lg: 16px;
  --space-xl: 24px;

  /* Typography */
  --font-display: 'Nunito', 'PingFang SC', 'Hiragino Sans GB', sans-serif;
  --font-body:    'DM Sans', 'PingFang SC', 'Hiragino Sans GB', sans-serif;

  /* Easing */
  --ease-expo:  cubic-bezier(0.16, 1, 0.3, 1);
  --ease-quart: cubic-bezier(0.25, 1, 0.5, 1);
  --ease-spring:cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Extra */
  --bg-muted:  #E8F1F4;
  --border-medium: #5EEAD4;
  --touch: 44px;

  /* Compatibility aliases (original variable names) */
  --text-primary:   #134E4A;
  --text-secondary: #0F766E;
  --text-tertiary:  #64748B;
  --text-inverse:   #FFFFFF;
  --text-muted:     #64748B;
  --border-light:   #CCFBF1;
  --border-card:    #CCFBF1;
  --font-sans:      var(--font-body);
  --font-mono:      'SF Mono','Menlo','Consolas',monospace;
  --font-family:    var(--font-body);
  --touch-min:      44px;
  --ease-out:       var(--ease-quart);
  --duration-fast:  0.15s;
  --duration-normal:0.25s;
  --space-2xl:      24px;
  --theme-primary:        var(--color-primary);
  --theme-primary-light:  var(--color-primary-light);
  --theme-primary-dark:   var(--color-primary-dark);
  --theme-gradient:       linear-gradient(135deg,var(--color-primary),var(--color-primary-dark));
  --theme-shadow:         0 4px 16px rgba(13,148,136,.22);
}

/* Mode overrides */
body.mode-preview {
  --color-primary:#D97706;--color-primary-light:#FEF3C7;--color-primary-dark:#B45309;--color-primary-hover:#B45309;
}
body.mode-review {
  --color-primary:#7C3AED;--color-primary-light:#EDE9FE;--color-primary-dark:#6D28D9;--color-primary-hover:#6D28D9;
}

/* ==== Reset ==== */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{-webkit-text-size-adjust:100%;font-size:16px;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;-webkit-tap-highlight-color:transparent}
body{
  margin:0;padding:0;font-family:var(--font-body);font-size:16px;line-height:1.6;
  color:var(--color-text);background:var(--bg-page);
  height:100dvh;display:flex;flex-direction:column;overflow:hidden;
  max-width:480px;margin:0 auto;position:relative;font-weight:500;
}

/* ===================================================================
   LOGIN OVERLAY
   =================================================================== */
.login-overlay{
  position:fixed;inset:0;background:var(--bg-page);z-index:9999;
  display:flex;align-items:center;justify-content:center;padding:20px;
}
.login-overlay.hidden{display:none}
.login-card{
  background:var(--bg-card);border-radius:var(--radius-lg);
  padding:36px 24px;width:100%;max-width:360px;
  box-shadow:var(--shadow-lg);text-align:center;
  border:1px solid var(--color-border);
}
.login-icon{font-size:48px;margin-bottom:8px}
.login-title{font-family:var(--font-display);font-size:22px;font-weight:800;color:var(--color-text);margin-bottom:4px}
.login-subtitle{font-size:14px;color:var(--color-text-muted);margin-bottom:24px}
.login-card input{
  width:100%;padding:12px 14px;border:1.5px solid var(--color-border);border-radius:var(--radius-md);
  font-size:15px;margin-bottom:10px;box-sizing:border-box;outline:none;
  font-family:var(--font-body);font-weight:500;background:var(--bg-input);
  transition:border .2s var(--ease-quart);color:var(--color-text);
}
.login-card input:focus{border-color:var(--color-primary)}
.btn-login{
  width:100%;padding:13px;background:var(--color-primary);color:var(--color-white);
  border:none;border-radius:var(--radius-md);font-size:16px;font-weight:700;
  cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.btn-login:active{transform:scale(.97);background:var(--color-primary-dark)}
.login-switch{font-size:13px;color:var(--color-text-muted);margin-top:12px}
.login-link{color:var(--color-primary);font-weight:700;cursor:pointer}
.login-status{font-size:13px;margin-top:8px;color:var(--color-danger)}

/* ===================================================================
   HEADER
   =================================================================== */
.app-header{
  flex-shrink:0;display:flex;align-items:center;justify-content:space-between;
  padding:var(--space-md) var(--space-lg);background:var(--bg-card);
  min-height:50px;border-bottom:1px solid var(--color-border);
}
.app-header-left{
  display:flex;align-items:center;gap:var(--space-sm);border:none;
  background:none;cursor:pointer;font-family:var(--font-body);
  padding:var(--space-xs) var(--space-sm);border-radius:var(--radius-sm);
  transition:background .15s var(--ease-quart);min-width:0;flex:1;text-align:left;
}
.app-header-left:active{background:var(--color-primary-light)}
.header-list-icon{font-size:18px;flex-shrink:0}
.header-title-group{display:flex;flex-direction:column;min-width:0}
.app-title{font-family:var(--font-display);font-weight:800;font-size:16px;color:var(--color-text);line-height:1.2;letter-spacing:-.01em}
.conv-title{font-size:11px;color:var(--color-primary);font-weight:600;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:120px}
.app-header-actions{display:flex;gap:var(--space-sm);flex-shrink:0}
.header-action-btn{
  display:inline-flex;align-items:center;gap:3px;background:var(--bg-input);
  border:1px solid var(--color-border);color:var(--color-text-secondary);
  padding:6px 12px;border-radius:var(--radius-full);font-size:12px;font-weight:600;
  cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.header-action-btn:active{background:var(--color-primary-light);color:var(--color-primary);border-color:var(--color-primary)}

/* ===================================================================
   TAB PAGES
   =================================================================== */
.tab-page{flex:1;display:flex;flex-direction:column;overflow:hidden;min-height:0}
.page-scroll{flex:1;overflow-y:auto;-webkit-overflow-scrolling:touch}

/* ===================================================================
   HOME
   =================================================================== */
.home-scroll{
  display:flex;flex-direction:column;align-items:center;
  padding:var(--space-xl) var(--space-lg) var(--space-xl);
  background:var(--bg-card);text-align:center;animation:heroIn .5s var(--ease-expo);
}
@keyframes heroIn{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}

.home-avatar-wrap{margin-bottom:var(--space-lg);animation:float 3s var(--ease-quart) infinite}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-6px)}}
.home-avatar{width:80px;height:80px;border-radius:50%;object-fit:cover;background:var(--color-primary-light);border:3px solid var(--color-primary)}

.home-greeting{
  font-family:var(--font-display);font-weight:800;font-size:20px;
  color:var(--color-text);line-height:1.6;margin-bottom:var(--space-xl);
  max-width:300px;letter-spacing:-.01em;
}

/* Home action buttons */
.home-actions{display:flex;gap:var(--space-sm);width:100%;max-width:380px}
.home-btn{
  flex:1;display:flex;flex-direction:column;align-items:center;gap:var(--space-sm);
  padding:var(--space-xl) var(--space-lg);border-radius:var(--radius-lg);
  border:none;cursor:pointer;font-family:var(--font-body);transition:all .2s var(--ease-quart);
  -webkit-tap-highlight-color:transparent;
}
.home-btn:active{transform:scale(.96)}
.home-btn-icon{font-size:32px;line-height:1}
.home-btn-label{font-size:14px;font-weight:600;color:var(--color-text)}

.home-btn-chat{
  background:linear-gradient(135deg,var(--color-primary-light),#FEF3C7);
  border:1px solid var(--color-border);
}
.home-btn-chat:active{background:var(--color-primary-light)}

.home-btn-learn{
  background:linear-gradient(135deg,var(--color-primary),var(--color-primary-dark));
  color:var(--color-white);box-shadow:0 8px 24px rgba(13,148,136,.25);
}
.home-btn-learn:active{box-shadow:0 4px 12px rgba(13,148,136,.3)}
.home-btn-learn .home-btn-label{color:var(--color-white)}

/* Mode cards */
.home-mode-cards{display:flex;gap:var(--space-sm);width:100%;max-width:380px;margin-top:var(--space-md)}
.home-mode-card{
  flex:1;display:flex;flex-direction:column;align-items:center;gap:6px;
  padding:var(--space-lg) var(--space-sm);border-radius:var(--radius-md);
  border:1.5px solid var(--color-border);background:var(--bg-card);cursor:pointer;
  font-family:var(--font-body);transition:all .15s var(--ease-quart);
  -webkit-tap-highlight-color:transparent;
}
.home-mode-card:active{transform:scale(.95)}
.home-mode-icon{font-size:26px;line-height:1}
.home-mode-name{font-size:12px;font-weight:600;color:var(--color-text-secondary)}
.home-mode-blue{border-color:#5EEAD4}
.home-mode-blue:active{background:var(--color-primary-light);border-color:var(--color-primary)}
.home-mode-orange{border-color:#FDE68A}
.home-mode-orange:active{background:#FEF3C7;border-color:#D97706}
.home-mode-green{border-color:#DDD6FE}
.home-mode-green:active{background:#EDE9FE;border-color:#7C3AED}

/* ===================================================================
   CHAT
   =================================================================== */
.chat-scroll{flex:1;overflow-y:auto;-webkit-overflow-scrolling:touch;background:var(--bg-page)}

/* Mode tabs */
.mode-tabs{
  flex-shrink:0;display:flex;gap:var(--space-xs);
  padding:var(--space-md) var(--space-lg);background:var(--bg-card);
  border-bottom:1px solid var(--color-border);
}
.mode-tab{
  flex:1;padding:9px 0;border-radius:var(--radius-full);border:none;
  background:transparent;font-size:13px;font-weight:600;cursor:pointer;
  font-family:var(--font-body);color:var(--color-text-muted);
  transition:all .15s var(--ease-quart);
}
.mode-tab.active{background:var(--color-primary-light);color:var(--color-primary)}

/* Difficulty */
.difficulty-bar{
  flex-shrink:0;display:flex;align-items:center;gap:var(--space-sm);
  padding:var(--space-sm) var(--space-lg);background:var(--bg-card);
  font-size:13px;color:var(--color-text-muted);font-weight:600;
  border-bottom:1px solid var(--color-border);
}
.diff-btn{
  padding:5px 14px;border-radius:var(--radius-full);
  border:1px solid var(--color-border);background:var(--bg-card);
  font-size:12px;font-weight:600;cursor:pointer;
  font-family:var(--font-body);color:var(--color-text-secondary);
  transition:all .15s var(--ease-quart);
}
.diff-btn.active{background:var(--color-primary);color:var(--color-white);border-color:var(--color-primary)}

/* Messages */
.chat-messages{display:flex;flex-direction:column;gap:2px;padding:var(--space-md) 0 var(--space-xl)}
.chat-messages .chat-time{font-size:11px;color:var(--color-text-muted);padding:0 4px}

/* Empty state */
.chat-empty{
  display:flex;flex-direction:column;align-items:center;
  padding:80px var(--space-xl);text-align:center;
}
.chat-empty-icon{font-size:48px;margin-bottom:var(--space-lg);opacity:.45;animation:float 3s var(--ease-quart) infinite}
.chat-empty-text{font-size:15px;color:var(--color-text-muted)}

.answer-content.ai-answer{display:none}

/* Bubbles */
.chat-bubble{overflow-wrap:break-word;word-break:normal;animation:bubbleIn .3s var(--ease-expo)}
@keyframes bubbleIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}
.chat-bubble-user{
  align-self:flex-end;max-width:78%;
  background:var(--color-primary);color:var(--color-white);
  padding:12px 16px;border-radius:18px 18px 4px 18px;
  font-size:15px;line-height:1.6;margin:4px var(--space-lg);font-weight:500;
}
.chat-bubble-user .chat-time{text-align:right;color:rgba(255,255,255,.65)}
.chat-bubble-ai{
  align-self:flex-start;max-width:82%;
  background:var(--bg-card);color:var(--color-text);
  padding:14px 16px;border-radius:18px 18px 18px 4px;
  border:1px solid var(--color-border);
  font-size:15px;line-height:1.7;margin:4px var(--space-lg) 4px 52px;position:relative;
}
.chat-bubble-ai::before{content:'';position:absolute;left:-40px;top:4px;width:30px;height:30px;border-radius:50%;background:var(--color-primary)}
.chat-bubble-label{font-size:12px;color:var(--color-text-muted);margin-bottom:6px;display:flex;align-items:center}

/* Steps */
.chat-bubble-content .step-header{
  font-family:var(--font-display);font-weight:800;color:var(--color-primary);cursor:pointer;
  min-height:var(--touch);padding:6px 4px;border-bottom:1px dashed var(--color-border);margin-top:6px;
}
.chat-bubble-content .step-header .step-arrow{display:inline-block;margin-right:6px;font-size:10px;transition:transform .2s var(--ease-quart)}
.chat-bubble-content .step-header:active{background:var(--color-primary-light);border-radius:var(--radius-sm)}
.chat-bubble-content .step-body{padding:4px 0 4px 12px;display:none}
.chat-bubble-content .step-body.expanded{display:block}
.chat-bubble-content .error-message{
  background:#FEF2F2;border:1px solid #FECACA;border-radius:var(--radius-sm);
  padding:12px;font-size:14px;color:#991B1B;line-height:1.6;
}

/* Loading */
#loading{margin:12px 0}
.loading{display:flex;flex-direction:column;align-items:center;gap:var(--space-md);padding:var(--space-xl) 0;color:var(--color-text-muted);font-size:14px}
.loading-spinner{
  width:28px;height:28px;border:3px solid var(--color-border);
  border-top-color:var(--color-primary);border-radius:50%;animation:spin .7s linear infinite;
}
@keyframes spin{to{transform:rotate(360deg)}}

/* ===================================================================
   CHAT INPUT
   =================================================================== */
.chat-input-bar{
  flex-shrink:0;padding:var(--space-sm) var(--space-md) var(--space-md);
  padding-bottom:calc(var(--space-md) + env(safe-area-inset-bottom,0));
  background:rgba(255,255,255,.82);backdrop-filter:blur(24px) saturate(180%);
  -webkit-backdrop-filter:blur(24px) saturate(180%);
  border-top:1px solid rgba(255,255,255,.5);
  margin:0 var(--space-md) var(--space-md);
  border-radius:var(--radius-xl);
  box-shadow:0 -4px 20px rgba(19,78,74,.05),inset 0 1px 0 rgba(255,255,255,.6);
}
.ocr-loading{text-align:center;font-size:12px;color:var(--color-primary);padding:2px 0}
.input-row{display:flex;align-items:center;gap:var(--space-sm)}
.btn-camera{
  width:38px;height:38px;border-radius:50%;border:none;background:var(--bg-input);
  font-size:18px;cursor:pointer;flex-shrink:0;display:flex;align-items:center;justify-content:center;
  transition:all .15s var(--ease-quart);color:var(--color-text-muted);
}
.btn-camera:active{background:var(--color-primary-light);color:var(--color-primary);transform:scale(.9)}
.btn-pick-teacher{
  width:auto;height:38px;padding:2px 10px;border-radius:var(--radius-full);
  border:1px solid var(--color-border);background:var(--bg-input);
  font-size:10px;font-weight:600;cursor:pointer;font-family:var(--font-body);
  color:var(--color-text-muted);transition:all .15s var(--ease-quart);
  line-height:1.2;white-space:nowrap;flex-shrink:0;
}
.btn-pick-teacher:active{background:var(--color-primary-light);color:var(--color-primary)}
.input-msg{flex:1;padding:11px 16px;border:1.5px solid var(--color-border);border-radius:var(--radius-full);font-size:15px;outline:none;background:var(--bg-input);color:var(--color-text);font-family:var(--font-body);font-weight:500;transition:all .2s var(--ease-quart)}
.input-msg:focus{background:var(--bg-card);border-color:var(--color-primary);box-shadow:0 0 0 3px rgba(13,148,136,.08)}
.input-msg::placeholder{color:var(--color-text-muted)}
.btn-send{
  width:40px;height:40px;border-radius:50%;background:var(--color-primary);color:var(--color-white);
  border:none;cursor:pointer;flex-shrink:0;display:flex;align-items:center;justify-content:center;
  font-size:16px;box-shadow:0 4px 16px rgba(13,148,136,.2);transition:all .15s var(--ease-quart);
}
.btn-send:active{transform:scale(.85)}
.btn-send:disabled{background:var(--bg-muted);box-shadow:none;cursor:not-allowed}
.input-actions{display:flex;gap:var(--space-sm);margin-top:var(--space-sm);flex-wrap:wrap}
.btn-action{
  padding:7px 14px;border-radius:var(--radius-full);border:1px solid var(--color-border);
  background:var(--bg-card);font-size:12px;font-weight:600;color:var(--color-text-secondary);
  cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart);white-space:nowrap;
}
.btn-action:active{background:var(--color-primary-light);border-color:var(--color-primary);color:var(--color-primary);transform:scale(.96)}
.btn-action:disabled{opacity:.35;cursor:not-allowed}
.confidence-badge{display:inline-flex;align-items:center;padding:3px 10px;border-radius:var(--radius-full);font-size:11px;font-weight:700;margin-left:auto}
.confidence-badge.high{background:#D1FAE5;color:#065F46}
.confidence-badge.medium{background:#FEF3C7;color:#92400E}
.confidence-badge.low{background:#FEE2E2;color:#991B1B}
.btn-fb-correct{border-color:#A7F3D0;color:#065F46;background:#ECFDF5}
.btn-fb-correct.active{background:#A7F3D0}
.btn-fb-wrong{border-color:#FECACA;color:#991B1B;background:#FEF2F2}
.btn-fb-wrong.active{background:#FECACA}

/* ===================================================================
   BOTTOM TAB BAR
   =================================================================== */
.tab-bar{
  flex-shrink:0;height:60px;
  margin:0 var(--space-lg) var(--space-md);
  margin-bottom:calc(var(--space-md) + env(safe-area-inset-bottom,0));
  background:rgba(255,255,255,.82);backdrop-filter:blur(24px) saturate(200%);
  -webkit-backdrop-filter:blur(24px) saturate(200%);
  border-radius:var(--radius-xl);
  box-shadow:0 2px 20px rgba(19,78,74,.06),0 0 0 1px rgba(19,78,74,.03),inset 0 1px 0 rgba(255,255,255,.6);
  display:flex;align-items:center;justify-content:space-around;padding:4px;
}
.tab-item{
  flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;
  gap:2px;height:100%;border:none;background:none;cursor:pointer;
  color:var(--color-text-muted);transition:all .2s var(--ease-spring);
  font-family:var(--font-body);-webkit-tap-highlight-color:transparent;
  border-radius:26px;padding:4px 0;
}
.tab-item.active{background:rgba(13,148,136,.07);color:var(--color-primary)}
.tab-icon{font-size:1.1rem;transition:transform .15s var(--ease-quart)}
.tab-item.active .tab-icon{transform:translateY(-2px)}
.tab-label{font-size:10px;font-weight:700;letter-spacing:.04em;text-transform:uppercase}

/* ===================================================================
   REVIEW PAGE
   =================================================================== */
.review-entry-card{
  text-align:center;padding:var(--space-xl) var(--space-lg);
  background:var(--bg-card);border-radius:var(--radius-lg);
  border:1px solid var(--color-border);margin:var(--space-lg);
}
.review-entry-icon{font-size:3rem;margin-bottom:var(--space-md)}
.review-entry-title{font-family:var(--font-display);font-size:22px;font-weight:800;margin-bottom:6px}
.review-entry-desc{font-size:14px;color:var(--color-text-muted);margin-bottom:var(--space-xl)}
.review-summary{background:var(--color-primary-light);border-radius:var(--radius-md);padding:14px;font-size:15px;line-height:1.8;white-space:pre-wrap;overflow-wrap:break-word;word-break:normal}
.review-intro{font-size:14px;color:var(--color-text-muted);text-align:center;margin-bottom:var(--space-xl);line-height:1.6}
.review-last-title{font-size:15px;font-weight:700;color:var(--color-text)}

/* ===================================================================
   BUTTONS (shared)
   =================================================================== */
.btn{display:block;padding:13px;border:none;border-radius:var(--radius-md);font-size:15px;font-weight:600;font-family:var(--font-body);cursor:pointer;transition:all .15s var(--ease-quart)}
.btn:active{transform:scale(.97)}
.btn-primary{background:var(--color-primary);color:var(--color-white)}
.btn-primary:active{background:var(--color-primary-dark)}
.btn-outline{border:1.5px solid var(--color-primary);background:transparent;color:var(--color-primary)}
.btn-outline:active{background:var(--color-primary-light)}
.btn-full{width:100%}
.btn:disabled{opacity:.35;cursor:not-allowed;pointer-events:none}

/* ===================================================================
   TEACHERS PAGE
   =================================================================== */
.page-title{font-family:var(--font-display);font-size:20px;font-weight:800;color:var(--color-text);padding:var(--space-xl) var(--space-lg) var(--space-md)}
.teacher-list{display:flex;flex-direction:column;gap:var(--space-sm);padding:0 var(--space-lg)}
.teacher-item{
  display:flex;align-items:center;gap:var(--space-md);padding:var(--space-lg);
  background:var(--bg-card);border-radius:var(--radius-lg);
  border:1.5px solid transparent;cursor:pointer;transition:all .15s var(--ease-quart);
}
.teacher-item:active{transform:scale(.98);border-color:var(--color-primary);background:var(--color-primary-light)}
.teacher-item.active{border-color:var(--color-primary);background:rgba(13,148,136,.04)}
.teacher-avatar{width:48px;height:48px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:24px;background:var(--bg-muted);flex-shrink:0}
.avatar-text{color:var(--color-white);font-size:18px;font-weight:700;background:var(--color-primary)}
.avatar-photo{width:48px;height:48px;border-radius:50%;object-fit:cover}
.teacher-info{flex:1;min-width:0}
.teacher-name{font-family:var(--font-display);font-size:16px;font-weight:800;color:var(--color-text);margin-bottom:2px}
.teacher-subject{font-size:13px;color:var(--color-text-muted)}
.teacher-style-tag{display:inline-block;padding:2px 8px;border-radius:var(--radius-full);font-size:11px;background:var(--bg-muted);color:var(--color-text-secondary);margin-right:4px;margin-top:4px}
.teacher-desc{font-size:13px;color:var(--color-text-muted);margin-top:2px}
.teacher-series{font-size:12px;color:var(--color-text-muted);margin-top:2px}
.teacher-check{color:var(--color-primary);font-size:20px;flex-shrink:0}
.teacher-custom-badge{font-size:10px;padding:2px 8px;border-radius:var(--radius-full);background:linear-gradient(135deg,var(--color-primary),#2DD4BF);color:var(--color-white);font-weight:700}
.teacher-del-btn{border:none;background:none;font-size:16px;cursor:pointer;padding:4px;opacity:.4}
.teacher-del-btn:hover{opacity:1;color:var(--color-danger)}
#create-teacher-btn{padding:14px;border-radius:var(--radius-md);border:2px dashed var(--color-border);background:var(--bg-card);font-size:15px;font-weight:600;color:var(--color-text-secondary);cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart);width:calc(100% - 32px);margin:12px auto 0}
#create-teacher-btn:active{background:var(--color-primary-light);border-color:var(--color-primary);color:var(--color-primary)}
.settings-gear{text-align:center;padding:var(--space-xl) var(--space-lg)}
.settings-gear button{background:none;border:none;color:var(--color-text-muted);font-size:14px;cursor:pointer;font-family:var(--font-body)}

/* ===================================================================
   MINE PAGE
   =================================================================== */
.mine-card{
  display:flex;align-items:center;gap:var(--space-lg);
  padding:var(--space-lg) var(--space-xl);background:var(--bg-card);
  border-radius:var(--radius-lg);cursor:pointer;
  border:1px solid transparent;margin:var(--space-xs) var(--space-lg);
  transition:all .15s var(--ease-quart);
}
.mine-card:active{background:var(--color-primary-light);border-color:var(--color-border)}
.mine-card-icon{font-size:24px;width:44px;height:44px;border-radius:var(--radius-md);display:flex;align-items:center;justify-content:center;background:var(--bg-muted);flex-shrink:0}
.mine-card-title{display:block;font-family:var(--font-display);font-size:16px;font-weight:800;color:var(--color-text);margin-bottom:2px}
.mine-card-desc{display:block;font-size:13px;color:var(--color-text-muted)}

/* Schedule settings */
.settings-section{
  margin:var(--space-lg);padding:var(--space-xl) var(--space-lg);
  background:var(--bg-card);border-radius:var(--radius-lg);
  border:1px solid var(--color-border);
}
.settings-section-title{font-family:var(--font-display);font-size:16px;font-weight:800;color:var(--color-text);margin-bottom:4px}
.settings-hint{font-size:13px;color:var(--color-text-muted);margin-bottom:var(--space-lg);line-height:1.5}
.settings-field{margin-bottom:var(--space-lg)}
.settings-field label{display:block;font-family:var(--font-display);font-size:13px;font-weight:800;color:var(--color-text);margin-bottom:var(--space-sm)}
.settings-field select{
  width:100%;padding:11px 14px;border:1.5px solid var(--color-border);border-radius:var(--radius-md);
  font-size:14px;color:var(--color-text);background:var(--bg-input);font-family:var(--font-body);font-weight:500;
  appearance:none;-webkit-appearance:none;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath d='M6 8L1 3h10z' fill='%2364748B'/%3E%3C/svg%3E");
  background-repeat:no-repeat;background-position:right 14px center;
}
.settings-field select:focus{outline:none;border-color:var(--color-primary)}
.btn-settings-save{
  padding:11px 24px;background:var(--color-primary);color:var(--color-white);
  border:none;border-radius:var(--radius-md);font-size:14px;font-weight:700;cursor:pointer;
  font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.btn-settings-save:active{background:var(--color-primary-dark);transform:scale(.97)}
.settings-save-status{font-size:12px;color:var(--color-text-muted);margin-left:var(--space-sm)}

/* Feedback */
.feedback-section{
  margin:var(--space-lg);padding:var(--space-xl) var(--space-lg);
  background:var(--bg-card);border-radius:var(--radius-lg);border:1px solid var(--color-border);
}
.feedback-title{font-family:var(--font-display);font-size:16px;font-weight:800;color:var(--color-text);margin-bottom:var(--space-md)}
.feedback-textarea{
  width:100%;min-height:60px;padding:12px 14px;border:1.5px solid var(--color-border);
  border-radius:var(--radius-md);font-size:14px;font-family:var(--font-body);font-weight:500;
  resize:vertical;background:var(--bg-input);color:var(--color-text);line-height:1.5;
  margin-bottom:var(--space-sm);transition:border .15s var(--ease-quart);
}
.feedback-textarea:focus{outline:none;border-color:var(--color-primary)}
.feedback-contact{
  width:100%;padding:11px 14px;border:1.5px solid var(--color-border);
  border-radius:var(--radius-md);font-size:14px;font-family:var(--font-body);font-weight:500;
  background:var(--bg-input);color:var(--color-text);margin-bottom:var(--space-md);
  transition:border .15s var(--ease-quart);
}
.feedback-contact:focus{outline:none;border-color:var(--color-primary)}
.btn-feedback{
  padding:11px 24px;background:var(--color-primary);color:var(--color-white);
  border:none;border-radius:var(--radius-md);font-size:14px;font-weight:700;cursor:pointer;
  font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.btn-feedback:active{background:var(--color-primary-dark);transform:scale(.97)}
.feedback-status{font-size:12px;color:var(--color-text-muted);margin-left:var(--space-sm)}

/* ===================================================================
   STATS PAGE
   =================================================================== */
.stats-summary{display:grid;grid-template-columns:repeat(3,1fr);gap:var(--space-sm);padding:var(--space-lg)}
.stat-card{
  background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-lg) var(--space-sm);
  text-align:center;border:1px solid var(--color-border);
}
.stat-card .stat-num{font-family:var(--font-display);font-size:28px;font-weight:800;color:var(--color-text);line-height:1;display:block;letter-spacing:-.02em}
.stat-card .stat-label{font-size:11px;color:var(--color-text-muted);margin-top:6px;display:block;font-weight:600}
.stats-empty{text-align:center;padding:60px var(--space-xl)}
.stats-empty-icon{font-size:48px;margin-bottom:var(--space-md);opacity:.4}
.stats-empty-text{font-size:15px;color:var(--color-text-secondary);margin-bottom:4px}
.stats-empty-hint{font-size:13px;color:var(--color-text-muted)}
.stats-section-title{font-family:var(--font-display);font-size:16px;font-weight:800;color:var(--color-text);padding:0 var(--space-lg);margin-bottom:var(--space-md)}
.stats-records{display:flex;flex-direction:column;gap:var(--space-sm)}
.lr-item{
  background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-lg);
  margin:0 var(--space-lg) var(--space-sm);border:1px solid var(--color-border);
  display:flex;align-items:flex-start;gap:var(--space-md);
}
.lr-header{display:flex;align-items:center;gap:var(--space-sm);margin-bottom:4px;font-size:12px;color:var(--color-text-muted);flex-wrap:wrap}
.lr-time{color:var(--color-text-muted)}
.lr-subject{font-size:11px;padding:2px 8px;border-radius:var(--radius-full);background:var(--color-primary-light);color:var(--color-primary);font-weight:600}
.lr-question{font-size:14px;color:var(--color-text);line-height:1.5}
.lr-kp{font-size:12px;color:var(--color-primary);margin-top:4px;font-weight:600}
.lr-icon{width:40px;height:40px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:18px;flex-shrink:0}
.lr-icon-tutoring{background:#CCFBF1}.lr-icon-preview{background:#FEF3C7}.lr-icon-review{background:#EDE9FE}
.lr-content{flex:1;min-width:0}
.lr-title{font-family:var(--font-display);font-size:14px;font-weight:800;color:var(--color-text);line-height:1.5;margin-bottom:4px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.lr-meta{font-size:12px;color:var(--color-text-muted)}
.lr-arrow{font-size:16px;color:var(--color-text-muted);flex-shrink:0;align-self:center}

/* ===================================================================
   ERROR BOOK
   =================================================================== */
.errorbook-scroll{flex:1;overflow-y:auto;-webkit-overflow-scrolling:touch;padding:var(--space-lg)}
.eb-summary{background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-xl);margin-bottom:var(--space-lg);border:1px solid var(--color-border)}
.eb-stats-row{display:flex;justify-content:space-around;margin-bottom:var(--space-lg)}
.eb-stat-item{display:flex;flex-direction:column;align-items:center;gap:4px}
.eb-stat-num{font-family:var(--font-display);font-size:28px;font-weight:800;color:var(--color-text);line-height:1;letter-spacing:-.02em}
.eb-stat-label{font-size:12px;color:var(--color-text-muted)}
.eb-stats-actions{display:flex;gap:var(--space-sm)}
.eb-review-all-btn{flex:1;padding:10px;border:none;border-radius:var(--radius-sm);background:#D1FAE5;color:#065F46;font-size:13px;font-weight:700;cursor:pointer;font-family:var(--font-body)}
.eb-review-all-btn:active{background:#A7F3D0}
.eb-export-btn{flex:1;padding:10px;border:none;border-radius:var(--radius-sm);background:var(--bg-muted);color:var(--color-text-secondary);font-size:13px;font-weight:600;cursor:pointer;font-family:var(--font-body)}
.eb-export-btn:active{background:var(--color-border)}
.eb-filters{margin-bottom:var(--space-md)}
.eb-filter-row{display:flex;gap:6px;overflow-x:auto;padding-bottom:4px;margin-bottom:6px;-webkit-overflow-scrolling:touch}
.eb-filter-tag{padding:7px 16px;border-radius:var(--radius-full);border:1px solid var(--color-border);background:var(--bg-card);font-size:13px;font-weight:600;color:var(--color-text-secondary);cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart);white-space:nowrap}
.eb-filter-tag.active{background:var(--color-primary);color:var(--color-white);border-color:var(--color-primary)}
.add-mistake-btn{width:100%;padding:14px;border-radius:var(--radius-md);border:2px dashed var(--color-border);background:var(--bg-card);font-size:14px;font-weight:600;color:var(--color-text-secondary);cursor:pointer;font-family:var(--font-body);margin-bottom:var(--space-lg);transition:all .15s var(--ease-quart)}
.add-mistake-btn:active{background:var(--color-primary-light);border-color:var(--color-primary);color:var(--color-primary)}
.eb-list{display:flex;flex-direction:column;gap:var(--space-sm)}
.eb-card{background:var(--bg-card);border-radius:var(--radius-lg);border:1px solid var(--color-border);overflow:hidden;transition:all .15s var(--ease-quart)}
.eb-card:active{transform:scale(.985)}
.eb-card-header{padding:var(--space-lg);cursor:pointer;display:flex;align-items:flex-start;justify-content:space-between;gap:var(--space-sm)}
.eb-subj-tag{display:inline-block;padding:3px 10px;border-radius:var(--radius-full);font-size:11px;font-weight:600;flex-shrink:0}
.eb-tag{display:inline-block;padding:3px 10px;border-radius:var(--radius-full);font-size:11px;font-weight:600}
.eb-q{flex:1;font-size:13px;color:var(--color-text);overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-weight:500}
.eb-time{font-size:11px;color:var(--color-text-muted);flex-shrink:0}
.eb-arrow{font-size:12px;color:var(--color-text-muted);transition:transform .2s var(--ease-quart);flex-shrink:0}
.eb-expanded .eb-arrow{transform:rotate(180deg)}
.eb-card-body{display:none;padding:0 var(--space-lg) var(--space-lg);border-top:1px solid var(--color-border);margin:0 var(--space-lg)}
.eb-expanded .eb-card-body{display:block}
.eb-kp{font-size:12px;color:var(--color-primary);margin-bottom:6px;font-weight:600}
.eb-full-question{padding:var(--space-md);background:var(--bg-input);border-radius:var(--radius-sm);font-size:14px;line-height:1.6;color:var(--color-text);margin-top:var(--space-md);white-space:pre-wrap;overflow-wrap:break-word;word-break:normal}
.eb-reply{margin-top:var(--space-sm);padding:var(--space-md);background:var(--bg-muted);border-radius:var(--radius-sm);font-size:14px;line-height:1.6;color:var(--color-text-secondary)}
.eb-notes{margin-top:var(--space-sm);padding:var(--space-sm) var(--space-md);background:#FFF7ED;border-radius:var(--radius-sm);font-size:13px;line-height:1.5;color:#78350F;cursor:text}
.eb-notes-edit{width:100%;padding:8px;border:1px solid var(--color-primary);border-radius:var(--radius-sm);font-size:13px;font-family:var(--font-body);resize:vertical;outline:none;background:var(--bg-card);min-height:60px}
.eb-actions{display:flex;gap:var(--space-sm);margin-top:var(--space-md);flex-wrap:wrap}
.eb-actions button{padding:7px 14px;border-radius:var(--radius-full);border:1px solid var(--color-border);background:var(--bg-card);font-size:12px;color:var(--color-text-secondary);cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart)}
.eb-actions button:active{background:var(--color-primary-light);border-color:var(--color-primary);color:var(--color-primary)}
.eb-empty{text-align:center;padding:60px var(--space-xl)}
.eb-empty-icon{font-size:52px;margin-bottom:var(--space-lg);opacity:.5}
.eb-empty p{font-size:14px;color:var(--color-text-secondary);margin-bottom:4px}
.eb-empty-btn{margin-top:14px;padding:10px 24px;background:var(--color-primary);color:var(--color-white);border:none;border-radius:var(--radius-sm);font-size:13px;font-weight:600;cursor:pointer;font-family:var(--font-body)}

/* Export */
.export-range-btn,.export-fmt-btn{flex:1;padding:10px 8px;border-radius:var(--radius-sm);border:1.5px solid var(--color-border);background:var(--bg-card);font-size:13px;color:var(--color-text-secondary);cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart)}
.export-range-btn.active,.export-fmt-btn.active{border-color:var(--color-primary);background:var(--color-primary-light);color:var(--color-primary);font-weight:700}

/* ===================================================================
   MODALS
   =================================================================== */
.modal{position:fixed;top:0;left:0;right:0;bottom:0;z-index:1000;display:flex;align-items:flex-end;justify-content:center;visibility:visible;opacity:1;transition:visibility 0s,opacity .25s var(--ease-quart)}
.modal.hidden{visibility:hidden;opacity:0;transition:visibility 0s .3s,opacity .25s var(--ease-quart)}
.modal-backdrop{position:absolute;top:0;left:0;right:0;bottom:0;background:rgba(19,78,74,.3);backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);transition:opacity .25s var(--ease-quart)}
.modal.hidden .modal-backdrop{opacity:0}
.modal-content{position:relative;background:var(--bg-card);border-radius:var(--radius-xl) var(--radius-xl) 0 0;width:100%;max-width:480px;max-height:85vh;overflow-y:auto;-webkit-overflow-scrolling:touch;box-shadow:0 -4px 32px rgba(19,78,74,.1);transform:translateY(0);transition:transform .35s var(--ease-spring);padding:var(--space-xl) var(--space-lg) var(--space-xl)}
.modal.hidden .modal-content{transform:translateY(100%)}
.modal-content::before{content:'';display:block;width:36px;height:5px;background:var(--color-border);border-radius:3px;margin:0 auto var(--space-lg)}
.modal-header{display:flex;align-items:center;justify-content:space-between;padding:0 0 var(--space-lg);border-bottom:1px solid var(--color-border);margin-bottom:var(--space-lg)}
.modal-header h3{font-family:var(--font-display);font-size:18px;font-weight:800;color:var(--color-text)}
.modal-close{width:32px;height:32px;border-radius:50%;border:none;background:var(--bg-input);font-size:20px;color:var(--color-text-muted);cursor:pointer;display:flex;align-items:center;justify-content:center;transition:all .15s var(--ease-quart)}
.modal-close:active{background:var(--bg-muted)}
.modal-body{padding:0}

/* ===================================================================
   FORMS
   =================================================================== */
.form-group{margin-bottom:var(--space-xl)}
.form-group label{display:block;font-family:var(--font-display);font-size:14px;font-weight:800;color:var(--color-text);margin-bottom:var(--space-sm)}
.form-group textarea{width:100%;min-height:50px;padding:12px 14px;border:1.5px solid var(--color-border);border-radius:var(--radius-md);font-size:15px;font-family:var(--font-body);font-weight:500;resize:vertical;background:var(--bg-input);color:var(--color-text);line-height:1.5;transition:border .15s var(--ease-quart)}
.form-group textarea:focus{outline:none;border-color:var(--color-primary)}
.selector{width:100%;padding:12px 14px;border:1.5px solid var(--color-border);border-radius:var(--radius-md);font-size:15px;color:var(--color-text);background:var(--bg-input);font-family:var(--font-body);font-weight:500;appearance:none;-webkit-appearance:none;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath d='M6 8L1 3h10z' fill='%2364748B'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 14px center}
.selector:focus{outline:none;border-color:var(--color-primary)}
.toggle-btns{display:flex;gap:var(--space-sm)}
.btn-toggle{flex:1;padding:10px;border-radius:var(--radius-md);border:1.5px solid var(--color-border);background:var(--bg-card);font-size:14px;cursor:pointer;font-family:var(--font-body);color:var(--color-text-muted);transition:all .15s var(--ease-quart)}
.btn-toggle.active{background:var(--color-primary);color:var(--color-white);border-color:var(--color-primary)}
.emoji-toggle{display:flex;gap:var(--space-sm)}
.btn-emoji{flex:1;display:flex;flex-direction:column;align-items:center;gap:6px;padding:14px 8px;border-radius:var(--radius-md);border:1.5px solid var(--color-border);background:var(--bg-card);cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart)}
.btn-emoji .emoji-big{font-size:28px}
.btn-emoji .emoji-label{font-size:12px;color:var(--color-text-muted)}
.btn-emoji.active{border-color:var(--color-primary);background:var(--color-primary-light)}
.btn-emoji.active .emoji-label{color:var(--color-primary);font-weight:700}
.form-input{width:100%;padding:12px 14px;border:1.5px solid var(--color-border);border-radius:var(--radius-md);font-size:15px;color:var(--color-text);background:var(--bg-input);font-family:var(--font-body);font-weight:500;resize:vertical;box-sizing:border-box;transition:border .15s var(--ease-quart)}
.form-input:focus{outline:none;border-color:var(--color-primary)}
.form-input::placeholder{color:var(--color-text-muted)}
.form-hint{font-size:12px;color:var(--color-text-muted);line-height:1.5;margin-top:6px}

/* ===================================================================
   CREATE TEACHER
   =================================================================== */
.ct-card{flex:1;padding:14px 10px;border-radius:var(--radius-md);border:1.5px solid var(--color-border);background:var(--bg-card);cursor:pointer;font-size:14px;font-weight:600;color:var(--color-text-secondary);font-family:var(--font-body);text-align:center;transition:all .15s var(--ease-quart)}
.ct-card.active{border-color:var(--color-primary);background:var(--color-primary-light);color:var(--color-primary)}
.ct-card small{display:block;font-size:11px;font-weight:500;opacity:.7;margin-top:2px}
.ct-subjects,.ct-gender,.ct-age{display:flex;gap:var(--space-sm)}
.ct-tags{display:flex;flex-wrap:wrap;gap:var(--space-sm)}
.ct-tag{padding:8px 16px;border-radius:var(--radius-full);border:1.5px solid var(--color-border);background:var(--bg-card);font-size:13px;color:var(--color-text-secondary);cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart)}
.ct-tag.active{border-color:var(--color-primary);background:var(--color-primary-light);color:var(--color-primary);font-weight:700}

/* ===================================================================
   SHARE
   =================================================================== */
.share-card{background:linear-gradient(135deg,#CCFBF1,#F0FDFA);border-radius:var(--radius-lg);padding:var(--space-xl);margin-bottom:var(--space-lg);text-align:center}
.share-card-top{font-size:13px;color:var(--color-primary);font-weight:700;margin-bottom:var(--space-md)}
.share-card-body{background:var(--bg-card);border-radius:var(--radius-md);padding:14px;margin-bottom:10px;border:1px solid var(--color-border)}
.share-card-question{font-size:14px;color:var(--color-text);line-height:1.5;margin-bottom:6px}
.share-card-teacher{font-size:12px;color:var(--color-text-muted)}
.share-card-point{font-size:13px;color:var(--color-text-secondary);margin-bottom:12px}
.share-card-bottom{font-size:12px;color:var(--color-text-muted)}
.share-card-qr-box{width:60px;height:60px;margin:8px auto 0;background:var(--bg-card);border-radius:var(--radius-sm);display:flex;align-items:center;justify-content:center;font-size:28px}
#share-screenshot{background:var(--color-primary);color:var(--color-white);border:none;width:100%;padding:14px;border-radius:var(--radius-md);font-size:15px;font-weight:600;cursor:pointer;font-family:var(--font-body);margin-bottom:8px}
#share-copy-link,#share-wechat{background:var(--bg-card);color:var(--color-text);border:1.5px solid var(--color-border);width:100%;padding:14px;border-radius:var(--radius-md);font-size:15px;font-weight:500;cursor:pointer;font-family:var(--font-body);margin-bottom:8px}
.share-hint{font-size:12px;color:var(--color-text-muted);text-align:center;margin-top:4px}

/* ===================================================================
   TOAST
   =================================================================== */
.toast{position:fixed;top:60px;left:50%;z-index:2000;padding:12px 24px;background:#134E4A;color:var(--color-white);border-radius:var(--radius-md);font-size:14px;font-weight:600;font-family:var(--font-body);box-shadow:var(--shadow-lg);opacity:1;transform:translateX(-50%) translateY(0);transition:opacity .25s var(--ease-quart),transform .25s var(--ease-quart);max-width:90vw;text-align:center;pointer-events:none}
.toast.hidden,.toast.hiding{display:block!important;opacity:0;transform:translateX(-50%) translateY(-8px)}

/* ===================================================================
   CONVERSATION LIST
   =================================================================== */
.conv-list{display:flex;flex-direction:column;gap:6px;margin-top:var(--space-md);max-height:50vh;overflow-y:auto}
.conv-list>div{padding:14px 16px;background:var(--bg-card);border-radius:var(--radius-md);border:1px solid var(--color-border);cursor:pointer;transition:all .15s var(--ease-quart);font-size:14px;color:var(--color-text)}
.conv-list>div:active{background:var(--bg-input)}
.conv-item{display:flex;align-items:center;justify-content:space-between;padding:12px;border:1px solid var(--color-border);border-radius:var(--radius-md);cursor:pointer;transition:all .15s var(--ease-quart);background:var(--bg-card);gap:10px}
.conv-item.active{border-color:var(--color-primary);background:var(--color-primary-light)}
.conv-item-main{flex:1;min-width:0}
.conv-item-title{font-family:var(--font-display);font-size:15px;font-weight:800;color:var(--color-text);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.conv-item-meta{display:flex;align-items:center;gap:8px;margin-top:2px;font-size:12px;color:var(--color-text-muted)}
.conv-item-subject{font-size:11px;padding:2px 8px;border-radius:var(--radius-full);background:var(--bg-muted);color:var(--color-primary);font-weight:600}
.conv-item-right{display:flex;align-items:center;gap:8px;flex-shrink:0}
.conv-item-time{font-size:11px;color:var(--color-text-muted)}
.conv-item-del{border:none;background:none;font-size:16px;cursor:pointer;opacity:.4;padding:4px;min-width:32px}
.conv-item-del:hover{opacity:1;color:var(--color-danger)}

/* Not understood menu */
.not-understood-menu{background:var(--bg-card);border-radius:var(--radius-md);box-shadow:var(--shadow-lg);padding:6px;display:flex;flex-direction:column;gap:4px;min-width:180px;animation:nufade .15s var(--ease-quart)}
@keyframes nufade{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}
.not-understood-menu button{border:none;background:none;padding:10px 14px;border-radius:var(--radius-sm);font-size:13px;cursor:pointer;text-align:left;font-family:var(--font-body);font-weight:500;transition:background .15s}
.not-understood-menu button:hover{background:var(--bg-input)}
.num-retry{color:var(--color-primary)}
.num-mark{color:var(--color-text-muted)}

/* ===================================================================
   ADAPTIVE PUSH CARD (P0 自适应教学)
   =================================================================== */
.adaptive-push-card{
  margin-top:16px;background:linear-gradient(135deg,#FEF3C7,#FEF2F2);
  border:1px solid #FECACA;border-radius:var(--radius-lg);padding:var(--space-xl);
  text-align:center;animation:bubbleIn .4s var(--ease-expo);
}
.push-card-text{font-size:14px;color:#7C2D12;line-height:1.7;margin-bottom:12px;font-weight:600}
.push-card-btn{
  display:inline-block;padding:11px 24px;background:#EA580C;color:#fff;
  border:none;border-radius:var(--radius-md);font-size:14px;font-weight:700;
  cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.push-card-btn:active{transform:scale(.96);opacity:.9}

/* ===================================================================
   AI QUICK ACTIONS
   =================================================================== */
.ai-quick-actions{display:flex;gap:var(--space-sm);margin-top:var(--space-sm);flex-wrap:wrap;padding:0 4px}

/* ===================================================================
   DAILY SUMMARY (学情 - 今日小结)
   =================================================================== */
.daily-summary-card{
  background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-xl);
  border:1px solid var(--color-border);margin-bottom:var(--space-md);
}
.daily-summary-empty{text-align:center;color:var(--color-text-muted);padding:var(--space-xl)}
.daily-summary-title{font-family:var(--font-display);font-size:16px;font-weight:800;margin-bottom:var(--space-md);color:var(--color-text)}
.daily-summary-stats{display:flex;gap:var(--space-md);flex-wrap:wrap;margin-bottom:var(--space-md)}
.daily-stat{font-size:13px;color:var(--color-text-secondary)}
.daily-stat strong{color:var(--color-text);font-family:var(--font-display);font-weight:800}
.daily-summary-detail{font-size:14px;line-height:1.8;color:var(--color-text);white-space:pre-wrap}
.daily-summary-points{display:flex;flex-wrap:wrap;gap:var(--space-sm);margin-top:var(--space-sm)}
.kp-tag{display:inline-block;padding:4px 12px;border-radius:var(--radius-full);font-size:12px;font-weight:600}
.kp-struggling{background:#FEF2F2;color:#991B1B;border:1px solid #FECACA}
.kp-mastered{background:#D1FAE5;color:#065F46;border:1px solid #A7F3D0}
.ds-p{font-size:14px;line-height:1.8;margin-bottom:8px;color:var(--color-text)}

/* ===================================================================
   TOMORROW SUGGESTIONS (明日建议)
   =================================================================== */
.tomorrow-section{background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-xl);border:1px solid var(--color-border);margin-bottom:var(--space-md)}
.tomorrow-title{font-family:var(--font-display);font-size:16px;font-weight:800;margin-bottom:var(--space-md);color:var(--color-text)}
.tomorrow-list{list-style:none;display:flex;flex-direction:column;gap:var(--space-sm)}
.tomorrow-item{
  display:flex;align-items:center;gap:var(--space-sm);padding:12px 14px;
  background:var(--bg-input);border-radius:var(--radius-md);cursor:pointer;
  transition:all .15s var(--ease-quart);font-size:14px;color:var(--color-text);
}
.tomorrow-item:active{background:var(--color-primary-light);color:var(--color-primary)}
.tomorrow-text{flex:1}
.tomorrow-arrow{color:var(--color-text-muted);font-size:14px}

/* ===================================================================
   WEEKLY REPORT (周报)
   =================================================================== */
.weekly-report-empty{text-align:center;padding:var(--space-xl);color:var(--color-text-muted);font-size:14px}
.weekly-report-card{
  background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-xl);
  border:1px solid var(--color-border);margin-bottom:var(--space-md);
}
.wr-p{font-size:14px;line-height:1.8;margin-bottom:8px;color:var(--color-text)}

/* ===================================================================
   EXAM SCORE (考试成绩)
   =================================================================== */
.exam-entry-card{
  background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-xl);
  border:1px solid var(--color-border);margin-bottom:var(--space-md);
}
.exam-entry-title{font-family:var(--font-display);font-size:16px;font-weight:800;margin-bottom:var(--space-md);color:var(--color-text)}
.exam-entry-fields{display:flex;align-items:center;gap:var(--space-sm);margin-bottom:var(--space-md)}
.exam-entry-fields input{
  flex:1;padding:11px 14px;border:1.5px solid var(--color-border);border-radius:var(--radius-md);
  font-size:15px;font-family:var(--font-body);font-weight:500;background:var(--bg-input);
  color:var(--color-text);transition:border .15s var(--ease-quart);
}
.exam-entry-fields input:focus{outline:none;border-color:var(--color-primary)}
.exam-score-divider{font-size:18px;font-weight:700;color:var(--color-text-muted)}
.btn-exam-save{
  padding:10px 24px;background:var(--color-primary);color:var(--color-white);
  border:none;border-radius:var(--radius-md);font-size:14px;font-weight:700;cursor:pointer;
  font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.btn-exam-save:active{background:var(--color-primary-dark);transform:scale(.97)}
.exam-trend-empty{text-align:center;padding:var(--space-xl);color:var(--color-text-muted);font-size:14px}
.exam-trend-card{
  background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-xl);
  border:1px solid var(--color-border);margin-bottom:var(--space-md);
}
.exam-trend-title{font-family:var(--font-display);font-size:16px;font-weight:800;margin-bottom:var(--space-md);color:var(--color-text)}

/* ===================================================================
   CHAT ENTRY (班主任谈心)
   =================================================================== */
.chat-entry-card{
  background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-xl);
  border:1px solid var(--color-border);margin-bottom:var(--space-md);text-align:center;
}
.chat-entry-title{font-family:var(--font-display);font-size:16px;font-weight:800;margin-bottom:8px;color:var(--color-text)}
.chat-entry-hint{font-size:14px;color:var(--color-text-muted);margin-bottom:var(--space-xl);line-height:1.6}
.btn-chat-entry{
  padding:12px 28px;background:var(--color-primary);color:var(--color-white);
  border:none;border-radius:var(--radius-md);font-size:15px;font-weight:700;cursor:pointer;
  font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.btn-chat-entry:active{background:var(--color-primary-dark);transform:scale(.97)}
.chat-response-bubble{
  background:var(--color-primary-light);border-radius:var(--radius-lg);padding:var(--space-xl);
  margin-bottom:var(--space-md);
}
.chat-response-text{font-size:14px;line-height:1.8;color:var(--color-text);white-space:pre-wrap}

/* ===================================================================
   PROFILE (学情诊断)
   =================================================================== */
.profile-section{background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-xl);border:1px solid var(--color-border);margin-bottom:var(--space-md)}
.profile-title{font-family:var(--font-display);font-size:16px;font-weight:800;margin-bottom:var(--space-md);color:var(--color-text)}
.profile-basic{display:flex;gap:var(--space-sm);flex-wrap:wrap;margin-bottom:var(--space-md)}
.profile-tag{display:inline-block;padding:4px 12px;border-radius:var(--radius-full);font-size:12px;font-weight:600}
.profile-name{background:var(--color-primary-light);color:var(--color-primary)}
.profile-level{background:var(--bg-muted);color:var(--color-text-secondary)}
.profile-subject{margin-bottom:var(--space-lg);padding-bottom:var(--space-md);border-bottom:1px solid var(--color-border)}
.profile-subj-header{font-family:var(--font-display);font-size:14px;font-weight:800;margin-bottom:var(--space-sm);color:var(--color-text)}
.profile-tags{display:flex;flex-wrap:wrap;gap:var(--space-sm);margin-bottom:var(--space-sm)}
.profile-weak{background:#FEF2F2;color:#991B1B;border:1px solid #FECACA}
.profile-strength{background:#D1FAE5;color:#065F46;border:1px solid #A7F3D0}
.profile-errors{font-size:13px;color:var(--color-text-muted);line-height:1.6;margin-top:var(--space-sm)}
.profile-style{font-size:14px;margin-top:var(--space-md);padding:var(--space-md);background:var(--bg-muted);border-radius:var(--radius-sm)}
.profile-insight{font-size:14px;margin-top:var(--space-md);padding:var(--space-md);background:linear-gradient(135deg,var(--color-primary-light),#FEF3C7);border-radius:var(--radius-sm);line-height:1.8}
.profile-actions{display:flex;gap:var(--space-sm);margin-top:var(--space-md)}
.btn-action-small{
  padding:7px 14px;border-radius:var(--radius-full);border:1px solid var(--color-border);
  background:var(--bg-card);font-size:12px;font-weight:600;color:var(--color-text-secondary);
  cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.btn-action-small:active{background:var(--color-primary-light);border-color:var(--color-primary);color:var(--color-primary)}
.btn-weekly{
  display:block;width:100%;padding:14px;margin:var(--space-md) 0;background:var(--color-primary);
  color:var(--color-white);border:none;border-radius:var(--radius-md);font-size:15px;
  font-weight:700;cursor:pointer;font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.btn-weekly:active{background:var(--color-primary-dark);transform:scale(.97)}

/* ===================================================================
   DIAGNOSIS (智能诊断)
   =================================================================== */
.diagnosis-section{background:var(--bg-card);border-radius:var(--radius-lg);padding:var(--space-xl);border:1px solid var(--color-border);margin-bottom:var(--space-md)}
.diagnosis-summary{font-size:14px;line-height:1.8;color:var(--color-text);margin-bottom:var(--space-lg);white-space:pre-wrap}
.diagnosis-alert{display:flex;gap:var(--space-md);padding:var(--space-md) var(--space-lg);border-radius:var(--radius-md);margin-bottom:var(--space-sm)}
.diagnosis-high{background:#FEF2F2;border-left:4px solid #DC2626}
.diagnosis-medium{background:#FEF3C7;border-left:4px solid #D97706}
.diagnosis-low{background:#D1FAE5;border-left:4px solid #059669}
.diag-icon{font-size:20px;flex-shrink:0}
.diag-body{flex:1;min-width:0}
.diag-title{font-weight:700;font-size:14px;color:var(--color-text);margin-bottom:2px}
.diag-detail{font-size:13px;color:var(--color-text-secondary);line-height:1.6}
.diagnosis-recs{display:flex;flex-direction:column;gap:var(--space-sm);margin-top:var(--space-lg)}
.diag-rec{font-size:14px;color:var(--color-text);line-height:1.6;padding:var(--space-sm) var(--space-md);background:var(--bg-input);border-radius:var(--radius-sm)}

/* ===================================================================
   GREETING OVERLAY (班主任弹窗)
   =================================================================== */
.greeting-overlay{
  position:fixed;inset:0;z-index:2000;display:flex;align-items:center;justify-content:center;
  background:rgba(19,78,74,.3);backdrop-filter:blur(6px);-webkit-backdrop-filter:blur(6px);
  padding:var(--space-xl);
}
.greeting-modal{
  background:var(--bg-card);border-radius:var(--radius-xl);width:100%;max-width:380px;
  box-shadow:0 8px 40px rgba(19,78,74,.15);overflow:hidden;animation:bubbleIn .35s var(--ease-spring);
}
.greeting-modal-header{display:flex;align-items:center;gap:var(--space-md);padding:var(--space-xl) var(--space-xl) var(--space-md)}
.greeting-modal-avatar{font-size:48px}
.greeting-modal-title{flex:1}
.greeting-modal-name{font-family:var(--font-display);font-size:18px;font-weight:800;color:var(--color-text)}
.greeting-modal-subtitle{font-size:12px;color:var(--color-text-muted)}
.greeting-modal-body{padding:0 var(--space-xl) var(--space-xl);font-size:14px;line-height:1.8;color:var(--color-text);white-space:pre-wrap}
.greeting-modal-actions{display:flex;flex-direction:column;gap:var(--space-sm);padding:0 var(--space-xl) var(--space-xl)}
.greeting-btn-chat,.greeting-btn-study,.greeting-btn-ok{
  padding:13px;border-radius:var(--radius-md);font-size:15px;font-weight:700;cursor:pointer;
  border:none;font-family:var(--font-body);transition:all .15s var(--ease-quart);
}
.greeting-btn-chat{background:var(--bg-muted);color:var(--color-text)}
.greeting-btn-chat:active{background:var(--color-border)}
.greeting-btn-study{background:var(--color-primary);color:var(--color-white)}
.greeting-btn-study:active{background:var(--color-primary-dark);transform:scale(.97)}
.greeting-btn-ok{background:var(--color-primary-light);color:var(--color-primary)}
.greeting-btn-ok:active{background:var(--color-border)}

/* ===================================================================
   PRINT EXPORT (打印导出)
   =================================================================== */
.card{background:#fff;border-radius:var(--radius-lg);padding:var(--space-xl);margin-bottom:var(--space-md);page-break-inside:avoid;border:1px solid #e2e8f0}
.card .subject{padding:3px 10px;border-radius:var(--radius-full);font-size:11px;font-weight:700;display:inline-block;margin-bottom:var(--space-sm)}
.card .subject.red{background:#fee2e2;color:#991b1b}
.card .subject.blue{background:#dbeafe;color:#1e40af}
.card .subject.green{background:#d1fae5;color:#065f46}
.card .question{font-size:14px;font-weight:600;color:#1e293b;margin-bottom:var(--space-sm)}
.card .answer{font-size:13px;color:#475569;line-height:1.7}
.card .answer p{margin-bottom:0}
.card .notes{font-size:12px;color:#92400e;margin-top:var(--space-sm);padding:8px;background:#fffbeb;border-radius:var(--radius-sm)}
.card .meta{font-size:11px;color:#94a3b8;margin-top:var(--space-sm)}
.date{font-size:12px;color:#94a3b8;text-align:center;margin:var(--space-lg) 0}

/* ===================================================================
   PICK AVATAR TEXT (更换老师按钮内小头像)
   =================================================================== */
.pick-avatar-text{
  display:inline-flex;align-items:center;justify-content:center;
  width:28px;height:28px;border-radius:50%;color:#fff;
  font-size:.875rem;font-weight:700;
}

/* ===================================================================
   TEACHER GROUP (老师分组)
   =================================================================== */
.teacher-group{margin-bottom:var(--space-md)}
.teacher-group-title{
  font-family:var(--font-display);font-size:14px;font-weight:800;color:var(--color-text-muted);
  padding:var(--space-sm) var(--space-lg);letter-spacing:.02em;
}

/* ===================================================================
   MISTAKE & TEACHER FORM CONTENT
   =================================================================== */
.mistake-form-content{max-height:80vh;overflow-y:auto}
.mistake-form-content .form-group{margin-bottom:14px}
.mistake-form-content .form-input{
  width:100%;padding:10px 12px;border:1px solid var(--color-border);
  border-radius:var(--radius-sm);font-size:14px;font-family:var(--font-body);
}
.mistake-form-content label{font-size:13px;color:var(--color-text-secondary);display:block;margin-bottom:4px}
.teacher-form-content{max-height:80vh}

/* ===================================================================
   UTILITIES
   =================================================================== */
.hidden{display:none!important}

/* ===================================================================
   REDUCED MOTION
   =================================================================== */
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}}